This invention relates to an apparatus for reproducing images recoded in respective frames of a developed film on a display device such as a monitor television.
There have been reproducing apparatuses which reproduce images recorded in respective frames of a developed film (hereinafter referred to as film images) on a monitor TV. The developed film is magnetically recorded with information regarding photographing conditions, developing conditions, reproducing conditions on specified portions. The magnetic information is read by a magnetic sensor. The film images are picked up by a color image sensor such as a CCD (Charge Coupled Device). After white balance correction, .gamma. correction, and other specified image processing, the picked up images are converted into a television signal of, e.g., NTSC system, and displayed on the monitor TV in accordance with reproducing conditions of the read magnetic information.
Further, the technology has been known of providing such reproducing apparatus with function of displaying so-called multi-image in which all the film images are arranged in a specified pattern on a display screen of a monitor TV to enable the operator to check all the film images at a single screen.
However, a long time has been spent until a multi-image is displayed on the display screen because it is necessary to read several kinds of information from the film, specifically, photographing condition information, developing condition information, reproducing condition information, and pick up film images at different speeds. Also, it will be apparent that the greater the number of film images, the longer the generating time of multi-image will become. In view thereof, there has been a big demand of displaying a multi-image in a shorter time after loading film on a reproducing apparatus.
Further, there has been a demand of viewing and seeing a clear multi-image and film image. To display the multi-image and reproduce film images clearly, it is necessary to pick up each film image at its suitable exposure control values. To set the exposure control values suitable for each film image, it is preferable to know an actual density of each film image on the loaded film, and calculate suitable exposure control values based on the image density in addition to the photographing condition and developing information. However, there has not yet been proposed any apparatus capable of detecting an actual density of film image before picking up of film images.
The photographing, developing, and reproducing condition information are recorded in the form of magnetic information. The magnetic information is written or recorded by the alternating current biasing method to reduce signal distortion which is otherwise likely to occur due to magnetic hysteresis. Accordingly, the developed film must be fed at a high speed to assure accurate reading of the magnetic information.
However, the picking up of film images for generation of multi-image and reproduction of film image cannot be executed at the same high speed as the reading of magnetic information. The picking up of film image for generation of multi-image can be executed at a higher speed than the picking up of film image for reproduction of film image because the display of multi-image need not so high quality as the reproduction of film image. However, the picking up of film image for multi-image cannot be executed at the same speed as the reading of magnetic information. Accordingly, the reading of magnetic information and picking up of film image must be executed at two different speeds, which will increase the processing time for generation of multi-image and reproduction of film image. Further, if detection of actual image density is executed, the processing time will further become longer.
Further, there has been the following problem in the reproduction of film images. In the processing of images picked up by a color sensor, an image signal representing the picked up image is processed without saturating its level even when a density range of an object is wide. Accordingly, a range of processable signal level is set relatively wide. When an object image having a narrow density range is picked up, a resolving power (dynamic range) of the signal level becomes relatively low, thereby relatively reducing the quality of the picked up image.
The developed color film assumes oranges and has a specified density level, even when it is not exposed. The film image in each frame has a density level according to a content of the image in addition to the orange density level, and a density distribution thereof includes an orange density distribution as a base. The orange base density differs depending upon the kind of film and development conditions, and varies among developed films.
Since the image picked up from the film image has an orange density level independently from the content of the image, the dynamic range becomes, in substance, narrow by the base density level in the image processing, thereby reducing the resolving power of the image.
Particularly, when the density range in the image processing is fixedly set, it is set relatively wide in view of the variation in the base density of the film and a margin for the image processing. Thus, in the case of the film image having a narrow density range, the dynamic range in the image processing becomes very narrow, making it difficult to process the image with high accuracy. As a result, the quality of the reproduced image will be considerably reduced.